等离子体激活电子束物理气相沉积NiCoCrAlY涂层的制备及微观组织结构研究

针对传统电子束物理气相沉积(EB-PVD)制备的柱状晶结构MCrAlY涂层存在线性缺陷的问题,本文建立了等离子体激活EB-PVD(PA EB-PVD)设备,并采用PA EB-PVD技术制备出了具有等轴晶结构的新型NiCoCrAlY涂层。结果表明,增大电弧放电电压和基板偏压均可以提高沉积粒子的能量。随着沉积粒子能量增强,涂层逐渐由柱状晶结构转变为致密等轴晶结构,晶粒尺寸增大;另一方面,涂层成份离析效应增强,主要体现在Al含量降低和Cr含量升高。

Microstructures of NiCoCrAlY Coatings Grown by Plasma Activated Electron Beam Physical Vapor Deposition

a novel technique-the plasma activated electron beam-physical vapor deposition(PAEB-PVD)-was developed by modifying the conventional electron beam physical vapor deposition(EB-PVD) to significantly reduce the columnar and linear defects of the NiCoCrAlY coatings,grown by EB-PVD.The high quality NiCoCrAlY coatings were deposited by the newly-developed technique.The impacts of the deposition conditions on microstructures and mechanical properties of the coating were evaluated.The results show that the energy of the impinging adatom strongly affects its microstructures.The energy of the adatom can be increased by increasing the arc discharge voltage and substrate bias.As the adatom energy increased,the columnar grains of the coating changed into the more compact equiaxial ones,accompanied with grain growth.Meanwhile,strong segregation was observed,resulting in an increased of Al content,a decreased Cr content,and an increase of plasticity.